PHP: 没有赋值为什么要修改值?

PHP: why the value is modified if there is no assign?

基本上没有太多关于它的,因为我把 echo 放在我的代码中。这是一个 CLI 脚本,应该是单线程的。

echo "$map: ".json_encode($map)."\n$mapHarvests: ".json_encode($mapHarvests)."\n";

foreach($map as $key => $section)
    if($players[$id]->pos < $section[0])
        break;

    elseif($players[$id]->pos < $section[1] && isset($mapHarvests[$key]))
    {
        $harvesters[$id] = [$currentTime, $key];
        break;
    }

echo "$map: ".json_encode($map)."\n$mapHarvests: ".json_encode($mapHarvests)."\n";

这是控制台输出的内容:

$map: [[-560,-240],[240,560]]
$mapHarvests: [[[0],1],[[1,2,3],1]]
$map: [[-560,-240],[240,560]]
$mapHarvests: [[[0],1],[240,560]]

为什么要修改$mapHarvests?我尝试将 isset()array_key_exists() 切换,结果相同。有更牛逼的看代码:

foreach($map as $key => $section)
    if(sectionStartsAfterPlayerPos())
        break;

    elseif(playerIsInSection() && sectionCanBeHarvested())
    {
        registerPlayer();
        break;
    }

编辑 1:变量是这样声明的:

$map = [0 => [-560, -240], 1 => [240, 560]];
$mapHarvests = [0 => [[0], 1], 1 => [[1, 2, 3], 1]];
$harvesters = [];
$currentTime = time(); // this one is inside the main loop

我发现了问题。在脚本的主循环中我也有这个东西:

if($currentTime - $settings->lastHarvestIncrease > 3)
{
    foreach($mapHarvests as &$section)
        if($section[$timeToHarvest] > 1)
            $section[$timeToHarvest] --;

    $settings->lastHarvestIncrease = $currentTime;
    $settings->save();
}

似乎将 section 更改为 section2 给出了正确的结果。 $section 仅在这两个部分中使用,它们位于对角,范围应该不同,但我想我不明白引用是如何工作的。